The present invention relates generally to agricultural equipment and, more particularly, to an implement having a tracked, steerable main carrier that is towed by a tractor or other suitable vehicle.
Current planter sizes continue to grow in working width size, from the increase in the number of row units being requested by customers, to increases in on-board product containers, in order to be more productive. In addition, larger horsepower tractors are being used to tow the implement which results in heavy frame structures. All of these factors have a significant contribution to increased weight on the implement.
For example, prior art implements have a main carrier which can be equipped with four (4) high flotation tires. This carrier serves multiple functions. First, it carries the most highly loaded part of the implement weight, i.e. the outer hitch, product containers and inner connection points to the wing booms. Second, it serves as the lift mechanism responsible for raising and lowering the planter to the proper heights for field operation and road transport. Lastly, it can be equipped with a steering system which allows for increased maneuverability of the machine when folded into transport position. Currently, the tires utilized on implements of this type are capable of supporting the weight of the implement in order to allow the implement to be effectively used and transported.
Also, as implements become longer, road transport maneuverability becomes critical, thus the need for steering. In addition, the adoption rate of vehicle guidance system has become quite high. Customers are requesting the ability to also control the implement position while performing in-field work.
As planting is a time sensitive operation, customers do not always wait until field conditions are ideal for operation of the implement. As a result, while the wheels of the implements are capable of adequately supporting the weight of the implement on a dry surface, on a wet surface, the weight of the implement combined with the soil conditions leads to the wheels of the implements sinking in soft wet soils or loose soils and ultimately stopping the planting operation as the unit becomes “stuck”. Customers are pressing manufactures for implements with the ability to have increased flotation on surfaces of this type.
To address the matter, prior art devices have been developed which replace the wheels with endless tracks. These types of tracks provide greater support for the implement on wet or loose soils, thereby lessening the potential for the implement becoming stuck.
However, when endless tracks are utilized on an implement, the connections between the tracks and the implement frame limit the ability of the implement to be steered in either the field and transport modes. This is due to the tracks becoming separated from the terrain during operation in either the field or transport mode, as well as during the transition between field and transport mode.
As a result, it is desirable to develop an implement employing an endless track motive system that overcomes the issues with prior art tracked implements.